Leucocyte 12-lipoxygenase

The primary hydroperoxy products can be further oxygenated at different positions, forming dihydroperoxy acids (diHpETE). Namely, porcine leucocyte 12-lipoxygenase converts 5S-HpETE into 5S,12S-diHpETE and 5S,15S-diHpETE, and 15S-HpETE into 14R,15S-diHpETE and 8S,15S-diHpETE [21],... 

Arachidonic acid is also metabolised by lipoxygenase to straight-chain hydroperoxy acids and then to leukotrienes which cause increased vascular permeability, vasoconstriction, bronchoconstriction, as well as chemotactic activity for leucocytes (whence their name). Inhibitors of lipoxygenase, e.g. zileuton, and leukotriene receptor antagonists, e.g. montelukast, zafirlukast, have found a place in the therapy of asthma (see p. 559). 

LEUKOTRIENE RECEPTOR AGONISTS act at receptors recognizing leukotrienes and analogues. The lipoxygenase system forms the leukotrienes, which are members of the eicosanoid family of phospholipid mediators. Their name derives from the fact that leukotrienes are found in leucocytes and contain a triene system of double bonds. The other members of the eicosanoid family are the prostanoids (thromboxanes and the prostaglandins), and these are formed by the cyclooxygenase system see cyclooxygenase INHIBITORS. All the eicosanoids are derived mainly from arachidonic acid. These mediators are synthesized on demand, and in some cases their half-lives are short. The... 

LOX, lipoxygenase P, platelet-type L, leucocyte-type h, human p, porcine. ... 

Soybean lipoxygenase-1 also acts as a 15-lipoxygenase for AA, but the amino acid identity between human 15-lipoxygenase and the soybean enzyme is only 22% [77]. cDNA encoding 15-lipoxygenase cloned from human bronchus cDNA library [78] is identical with that from human reticulocyte cDNA library [77]. Thus the presence of two forms of 15-lipoxygenase in a human leucocyte preparation [82] awaits further investigation. 

Platelet-type 12-lipoxygenase Leucocyte-type 12-lipoxygenase 15-Lipoxygenase... 

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